podhmo/Makefile

## main.go
package main

import (
	"fmt"
	"net/http"
	"os"
)

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, `<body>
		<a href="/download">download</a>
		<button>download from js</button>
		<script>
		document.querySelector("button").addEventListener("click", () => {
			window.open("/download");
		})
		</script>
		</body>`)
	})
	http.HandleFunc("/download", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Disposition", "attachment; filename=sample.txt")
		w.Header().Set("Content-Type", "plain/text")
		fmt.Fprintln(w, "Hello, World!")
	})

	addr := ":8080"
	fmt.Fprintln(os.Stderr, "listening on", addr)
	if err := http.ListenAndServe(addr, nil); err != nil {
		panic(err)
	}
}

## main.ts
import * as process from 'process';
import * as path from 'path';

import * as playwright from 'playwright';

async function main() {
    const browser = await playwright.chromium.launch({
        headless: false,
        args: ["--no-zygote", "--single-process", "--disable-extensions", "--incognito"],
        downloadsPath: process.cwd() + "/downloads"
    })
    const context = await browser.newContext();
    const page = await context.newPage();
    await page.goto("http://localhost:8080/", { waitUntil: 'domcontentloaded' });

    const downloadPromise = page.waitForEvent("download");
    console.log("click")
    await page.click("a");

    const download = await downloadPromise;
    download.saveAs(path.join(process.cwd(), "downloads", download.suggestedFilename()));
    console.log("done")
    await browser.close();
}
Promise.resolve(main()).catch(err => { console.log(err); process.exit(1); });

## main2.ts
import * as process from 'process';
import * as path from 'path';
import * as fs from 'fs/promises';

import * as playwright from 'playwright';


async function main() {
    const browser = await playwright.chromium.launch({
        headless: false,
        args: ["--no-zygote", "--single-process", "--disable-extensions", "--incognito"],
        downloadsPath: process.cwd() + "/downloads",
    })
    const context = await browser.newContext();
    const page = await context.newPage();
    await page.goto("http://localhost:8080/", { waitUntil: 'domcontentloaded' });

    console.log("click")

    const downloadPromise = new Promise<playwright.APIResponse>((resolve, reject) => {
        page.context().route("**/download", async (route, request) => {
            console.log("\troute start", request.url())
            // current page
            const originalResponse = await route.fetch();
            console.log("\troute internal response", request.url(), originalResponse.status())
            resolve(originalResponse);
            await route.fulfill({
                status: originalResponse.status(), body: "ok",
            })
            console.log("\troute end", request.url())
        }, { times: 1 })
    })

    await page.click("button");

    const response = await downloadPromise;
    await fs.writeFile(path.join(process.cwd(), "downloads", "sample.txt"), await response.body())
    console.log("done")

    await browser.close();
}
Promise.resolve(main()).catch(err => { console.log(err); process.exit(1); });

## Makefile
serve:
	go build -o /tmp/xxx main.go && /tmp/xxx
tree:
	tree .

click-a:
	DEBUG=pw:api npx tsx main.ts
click-button:
	DEBUG=pw:api npx tsx main2.ts
	package main

	import (
	"fmt"
	"net/http"
	"os"
	)

	func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintln(w, `<body>
	<a href="/download">download</a>
	<button>download from js</button>
	<script>
	document.querySelector("button").addEventListener("click", () => {
	window.open("/download");
	})
	</script>
	</body>`)
	})
	http.HandleFunc("/download", func(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Disposition", "attachment; filename=sample.txt")
	w.Header().Set("Content-Type", "plain/text")
	fmt.Fprintln(w, "Hello, World!")
	})

	addr := ":8080"
	fmt.Fprintln(os.Stderr, "listening on", addr)
	if err := http.ListenAndServe(addr, nil); err != nil {
	panic(err)
	}
	}
	import * as process from 'process';
	import * as path from 'path';

	import * as playwright from 'playwright';

	async function main() {
	const browser = await playwright.chromium.launch({
	headless: false,
	args: ["--no-zygote", "--single-process", "--disable-extensions", "--incognito"],
	downloadsPath: process.cwd() + "/downloads"
	})
	const context = await browser.newContext();
	const page = await context.newPage();
	await page.goto("http://localhost:8080/", { waitUntil: 'domcontentloaded' });

	const downloadPromise = page.waitForEvent("download");
	console.log("click")
	await page.click("a");

	const download = await downloadPromise;
	download.saveAs(path.join(process.cwd(), "downloads", download.suggestedFilename()));
	console.log("done")
	await browser.close();
	}
	Promise.resolve(main()).catch(err => { console.log(err); process.exit(1); });
	import * as process from 'process';
	import * as path from 'path';
	import * as fs from 'fs/promises';

	import * as playwright from 'playwright';


	async function main() {
	const browser = await playwright.chromium.launch({
	headless: false,
	args: ["--no-zygote", "--single-process", "--disable-extensions", "--incognito"],
	downloadsPath: process.cwd() + "/downloads",
	})
	const context = await browser.newContext();
	const page = await context.newPage();
	await page.goto("http://localhost:8080/", { waitUntil: 'domcontentloaded' });

	console.log("click")

	const downloadPromise = new Promise<playwright.APIResponse>((resolve, reject) => {
	page.context().route("**/download", async (route, request) => {
	console.log("\troute start", request.url())
	// current page
	const originalResponse = await route.fetch();
	console.log("\troute internal response", request.url(), originalResponse.status())
	resolve(originalResponse);
	await route.fulfill({
	status: originalResponse.status(), body: "ok",
	})
	console.log("\troute end", request.url())
	}, { times: 1 })
	})

	await page.click("button");

	const response = await downloadPromise;
	await fs.writeFile(path.join(process.cwd(), "downloads", "sample.txt"), await response.body())
	console.log("done")

	await browser.close();
	}
	Promise.resolve(main()).catch(err => { console.log(err); process.exit(1); });
	serve:
	go build -o /tmp/xxx main.go && /tmp/xxx
	tree:
	tree .

	click-a:
	DEBUG=pw:api npx tsx main.ts
	click-button:
	DEBUG=pw:api npx tsx main2.ts